Type-writer key-lock.



M. PPAU.

TYPE WRITER KEY LOOK.

I APPLICATION FILED APR.4,1911.

. [)7 verlfbr:

" 7(a) Pfaa- I COLUMBIA PIANOOIAHI CO WASHINGTON, D. C-

Patented Mar. 26; 1912.

9 w fifth/Crag UNITED STATES PATENT OEFICE.

IPFAU, OF WOODSTOCK, ILLINOIS, A SSIGNOR TO EMERSON TYPEWRITER COMPANY,

OF WOODSTOCK, ILLINOIS, A CORPORATION OF ILLINOIS.

TYPE-WRITER. KEY-LOCK.

Specification of Letters Patent.

Application filed. April 4, 191 1.

Patented Mar. 26, 1912.

Serial 1703618316.

. To all whom may concern:

Locks, of which the following is a specification.

The present invention relates to a device for locking the shiftinglevers employed with typewriters, whereby when it is desired to utilizecapital letters or figures for an extended period of time, the operatormay, by locking these shifting levers, utilize such characters withoutthe necessity of keeping his finger continually upon the levers to keepthem depressed.

The object of the present invention is to provide a mechanism foraccomplishing this locking operation which will be cheap and simple ofmanufacture, and which will contain no involved parts liable to becomedisplaced and so render the device inoperative.

Anotherobject'of the present invention is to provide 'a mechanism whichwill be compact in form and easily applicable to the body of thetypewriting machine without any change or addition to the constructionof the framework of the machine.

A "further object of the invention is to provide a mechanism which willpermit of the normal movementof the key levers wit-hout locking them inthrown position, and to actuate the mechanism so as to permit of theirbeing locked by merely increasing the degree of :pressure on the leverand depressing it below its normal line of depression.

A still further object of the invention is to provide means forautomatically returning the parts of the locking mechanism to normalposition, and which will be of a nature to assist in the lockingoperation.

The invention also consists inthe features of construction andth'ecombination of'parts hereinafter described and claimed.

*In the drawings, Figure 1 is anelevation of the mechanism of thepresent invention, showing the parts in :normal lpOSitiOIl; Fig. 2, aView similar to Fig. 1, showing the parts in the position assumed whenthe key levers are locked; Fig. 3, section on line 3 3 of Fig. 1,looking in the direction of the arrow; and Fig. 4, a detail showing aplan view of the stop member controlling the recess in which the keylever is inserted when it is desired to lock the same.

In typewri ting machines there are employed a series of levers known asshift-key levers, which are utilized for the purpose of shifting theposition of the writing mechanism so as to bring the capital letters orthe numerals into proper position to strike the writing line when thetype keys are operated. It frequently is desirable to maintain thisshifted position of the parts for a-considera'ble period of'tiine, andhence means are employed for locking these shiftkey levers in theirshifted position, so that a continual usage of the "capital letters ornumerals may be had. It is undesirable, however, that these lockingmechanisms should operate at each actuation of "the shift-key lever,since frequently the shifting of the parts is only employed for :theprinting of a single character, and, obviously, it' is not desirable tolock and unlock the lever every time ashifting of "the parts is desired.

It is the intention of the present invention The invention, asillustrated in the present drawings, consists of a plate 5 of suitablesize and formation, which :is'seo'ured to the body of the typewriter*by' any suitable meansyas, for instance, screws 6. The plate is.provided with :a series of longitudinally extending slots -7, 8 "and 9,two 'of which slots, -7 and 8, in the form shown are :in-

' creased in width at "their :lower end to :pro-

vide offset portions 10. :Itis understood that the number of these slotsis immaterial to the principle involved in "the present-invention, andthat one or :more slots :having this increased width may be employed, asdesired. I

-By enlarging the .slots 7 and 8 in the manner show-.11, a shoulder '11is (provided for each slot, under w ich shoulder the JB QI iS forcedduring the locking operation. It is desirable that the length of thatportion of the slots which is increased in width should normally be tooshort to receive the key lever, whereby, in the normal operation of thelever, no positioning of the lever within this increased portion ispossible, and hence no locking of the lever will occur during normaloperation; and it is further desir able that means should be providedwhich would act, when a greater than normal pressure is exerted on theshift lever, to remove theobstruction to the slot, so that that portionof the slot which is of increased width will be sufliciently long topermit of the insertion of the lever thereinto and the conse quentlocking of the lever. The mechanism for performing this obstructingoperation in the form shown in the drawings consists of avibrating oroscillating U-shaped member 12, which is pivoted at 18, and is formed ofa single sheet of metal Ushaped in crosssection, and comprising sidewalls 14 and a bottom wall 15. The bottom wall is cut away adjacent theends, as shown in Fig. 4, so as to provide ears 16 at one end thereof,which receives the pivot for the member 12 and a pair of ears 17 throughwhich extends a suitable pin 18 adapted to receive one end of a coiledspring 19,'the other end of the spring being secured in any suitablemanner.

As will be seen from a study of Figs. 1 and 2, the stop member 12surrounds the lower end of the slotted plate 5, and the side walls 14 ofthe stop member extend a distance upward sothat they cover the lower endof the enlarged port-ion of the slots and form an obstruction therefor.Thus, with the stop member in the position shown in Fig. 1, the lengthof the enlarged portion of the slot is decreased by reason of the factthat the side walls of the stop member are overlying the lower end ofthe plate 5 and cover the lower portion of the slots.

The operation of the device is as follows: Taking the parts as shown inFig. 1, when one of the levers 20 is depressed normally, that is, when anormal amount of pressure is exerted by the operator upon the lever, thelever will descend in the slot in which it travels until the lower endof the lever contacts, or approximately contacts, the upper edge of thestop member 12. But in such a movement, owing to the fact that the stopmember is overlying the lower end of the plate 5, the lower end of theslot, which is of increased width, will not be sufficiently long topermit of the insertion of the key lever thereinto. and hence no lockingof the lever will result in this normal operation. When, however, thekey lever is depressed into the position shown in Fig. 2, which positionis assumed when a greater force than normal is exerted on the lever bythe operator, the lever forces the obstructing member 12 into theposition shown in Fig. 2, in which position the member 12 is forceddownwardly and away from the plate 5; and thus the obstruction to theincreased portion of the slot is removed, so that the length of theincreased portion 10 of the slot is increased sufliciently to receivethe lever. After the depression of the lever sufficiently to lower thestop member 12 into the position shown in Fig. 2, a slight sidewisemovement of the lever will throw it so that it will rest under theshoulder 11, and thus will be locked in position.

As will be seen from a study of Fig. 2, when the lever is in lockedposition, the upper edge of the lever is engaged by the shoulder 11, andthe lower edge of the lever is engaged by the top face of the member 12.Since this member is under spring control, this serves to place thelever in engagement with a spring-controlled member which has a springpressure exerted thereon, normally tending to hold it in engagedposition with the lever; and thus this spring pressure serves toincrease the locking etliciency. The upward movement of the members islimited by the bottom wall 15 engaging the lower wall of the plate 5,and the member 12 is returned and maintained in normal position by thespring 19.

I claim:

1. A key-lever lock for typewriters, comprising a member having arecessed slot therein, and means operated by the movements of thekey-lever for increasing the normal length of said recessed portion,whereby the lever may be inserted within said recessed portion andlocked, substantially as described.

2. A key-lever lock for typewriters, comprising a member having arecessed slot therein. a vibratory member adapted to normally decreasethe length of the recessed portion of the slot to prevent entrance ofthe key-lever thereinto, a movement greater than normal of saidkey-lever moving said vibrating member to permit the insertion of thelever within said recessed portion, whereby the lever is locked,substantially as described.

3. A- key-lever lock for typewriters, comprising a member having arecessed slot therein, means operated by the movements of the key-leverfor increasing the normal length of said recessed portion, whereby thelever may be inserted within said recessed portion and locked, and meansfor automatically returning the parts controlling the length of therecessed portion to normal position. substantially as described.

1. A key-lever lock for typewriters, comprising a member having arecessed slot therein, a vibratory member adapted to normally decreasethe length of the recessed portion of the slot to prevent entrance ofthe key-lever thereinto, a movement greater than normal of saidkey-lever moving said vibrating member to permit the insertion ofscribed.

5. A key-lever lock for typewriters, comprising a member having arecessed slot therein, a vibrating member serving to normally decreasethe length of said recessed portion of the slot, whereby the key-leveris prevented from entering said slot when moved normally, a movement ofthe lever greater than normal moving said vibrating member into positionwhereby said lever can be inserted within the recessed portion of theslot and locked, said vibrating member engaging said lever in its lockedposition and assisting to maintain it in such position, substantially asdescribed.

6. A key-lever lock for typewriters, consisting of a member having arecessed slot therein, said recess being at the lower end of the slot, avibrating member overlying the lower edge of said slotted member andnormally decreasing the length of the recessed portion-of the slot toprevent the entrance of the key-lever thereinto, said lever when thrownto its farthest position moving said vibrating member into positionwhereby the key-lever may be inserted within the recessed portion of theslot and locked, subst-ant-ially as described.

7 A key-lever lock for type-writers, comprising a member having arecessed slot therein, a vibrating member serving to normally decreasethe length of said recessed portion of the slot, whereby the key-leveris prevented from entering said slot when moved normally, a movement ofthe lever greater than normal moving said vibrating member into positionwhereby said lever can be inserted within the recessed portion of theslot and locked, said vibrating member engaging said lever in its lockedposition and assisting to maintain it in such position, and tensionmechansm for returning the vibrating member to and maintaining it innormal posit-ion, substantially as described.

8. A key-lever lock for typewriters, comprising a member having arecessed slot therein, a vibrating member serving to normally decreasethe length of. said recessed portion of the slot, whereby the key-leveris prevented from entering said slot when moved normally, a movement ofthe lever greater than normal moving said vibrating member into positionwhereby said lever can be inserted within the recessed portion of theslot and locked, said vibrating member engaging said lever in its lockedposition and assisting to maintain it in such position, and means forlimiting the upward movement of said vibrating member, substantially asdescribed.

9. A key-lever lock for typewriters, comprising a member having arecessed slot therein, said recess being at the lower end of the slot, aU-shaped vibrating member embracing the lower end of the slotted memberand serving to decrease the length of the recessed portion of the slotto prevent the entrance of the key-lever thereinto, and adapted whenengaged and moved by the keylever to move into position to increase thelength of the recessed portion of the slot, whereby the key lever may beinserted within the recessed portion of the slot and locked,substantially as described.

10. A key-lever lock for typewriters, comprising a member having arecessed slot therein, said recess being at the lower end of the slot, a-U-shaped vibrating member embracing the lower end of the slotted memberand serving to decrease the length of the recessed portion of the slotto prevent the en trance of the key-lever thereinto, and adapted whenengaged and moved by the key lever to move into position to increase thelength of the recessed portion of the slot, whereby the key lever may beinserted within the recessed portion of the slot and locked, and tensionmechanism for automatically returning the vibrating member to normalposition, substantially as described.

11. A key-lever lock for typewriters, comprising a member having arecessed slot therein, said recess being at the lower end of the slot,means actuated by the movement of the keylevers for controlling thelength of the recessed portion of the slot, whereby a movement of thelever greater than normal moves the controlling means out of normalposition to permit of the insert-ion of the lever into the recessedportion of the slot, substantially as described.

12. A key-lever lock for typewriters, comprising a slotted member havingan oiiset portion providing a shoulder, and movable means for normallypreventing the keylevers from engaging said shoulder, a movement of saidlever greater than normal shifting said movable means, whereby the levercan be brought into engagement with said shoulder and locked,substantially as described.

MAX PFAU.

Vitnesses T. KEATING, EARLE E. BOWER.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

